The invention is concerned with a locking mechanism of a sliding door, in particular for motor vehicles, having a Bowden cable which can be actuated by door handles and acts on a locking element, having a moving-carriage support which is fitted to the sliding door and a moving carriage which runs in a guide rail, the relative position between the moving carriage and the moving-carriage support changing between the open and the closed position of the sliding door.
Locking mechanisms of this type of sliding door are used to lock the sliding door in the open position, for example to a closing bracket which is fitted to the vehicle body, in order to prevent the sliding door from sliding back into the closed position. The unlocking is done with the aid of the normal door handles which, when the sliding door is closed, are used for unlocking the door lock. However, it would be desirable to avoid, when the sliding door is closed, making the unlocking of the door lock more difficult because of the locking mechanism whose locking element has its own return spring.
Solutions are already known in which the locking mechanism is provided with a rotary falling-latch lock known from other door locks as the locking element, which rotary falling-latch lock can be locked in an open position and therefore disengages the door handles from the spring action of their restoring element. The increased structural complexity of the known rotary falling-latch locks, which consist of a large number of parts, and also their increased space requirement are disadvantageous in the case of a solution having a rotary falling latch.
The object of the invention consists in providing a locking mechanism for a sliding door, which mechanism has a simplified locking element and makes possible lower actuating forces for the door handles when the sliding door is closed.
According to the invention, the object is achieved in that in the case of a locking mechanism of the type described at the beginning, the moving-carriage support, during its movement relative to the moving carriage, shifts a driver which is guided on the moving carriage and during this movement carries along the locking element in the direction of its unlocked position.
The invention makes use of the characteristic feature present in general in many sliding doors and regularly present in the case of sliding doors in the motor-vehicle sector, in which the sliding door, as it closes, changes its position with respect to the guide rail, as a result of which the relative movement between the moving carriage and the moving-carriage support which is fitted to the sliding door changes. Since the locking mechanism is required only in the open position of the sliding door, in order to open the locking element which is latched into place, the relative movement of the moving carriage with respect to the moving-carriage support is used in order to move the locking element into its open position during the closing of the door, as a result of which the Bowden cable is also correspondingly moved and disengaged from the action of the restoring spring of the locking element.
The locking element does not necessarily have to be shifted into a position which corresponds to its unlocked position, but the actuating force of the door handles until the door lock is unlocked should not be increased.
The driver may act on a connecting element which connects the cable of the Bowden cable to the locking element, but it preferably acts on the cable of the Bowden cable which is directly connected to the locking element. The low number of parts associated with this solution causes a reduction in the production costs and in the construction space.
The locking mechanism according to the invention is suitable for constructions in which the moving carriage and moving-carriage support are secured pivotably to each other via a hinge, as is generally the case, but basically use in any type of guidance between the moving carriage and moving-carriage support is conceivable. In an embodiment having a hinge the cable of the Bowden cable may be guided around a deflection pulley which sits on the rotational axis of the hinge.
In a development of the invention, provision is preferably made for the moving-carriage support, during the transfer into the closed position, to rotate, via a driver device, the deflection pulley to whose circumference the cable is secured in a form-locking manner via the driver.
In this solution, which again manages with a very small number of parts, the deflection pulley, which is in any case advantageous, for the cable of the Bowden cable on the moving carriage is used to carry along the latter during the relative movement in order to shift the locking element in the direction of its unlocked position. In addition to that, the form-locking connection between the cable and the deflection pulley may also be used to avoid the cable springing down during the opening of the sliding door when the locking element slides over the closing bracket and as it does so is shifted back counter to the force of its restoring spring and disengaging the Bowden cable.
The locking mechanism according to the invention permits the locking element to be designed as a simple hook which, under the action of a spring, latches with the closing bracket (already discussed) in the completely open position of the sliding door. A hook of this type may replace the previously customary rotary falling-latch solution, the locking mechanism according to the invention ensuring the disengagement when the door handles are actuated.
The locking mechanism may be coupled to the door handles, for example by the Bowden cable being in engagement with connecting members between the door handles and the door lock, it being possible for this engagement to be canceled by closing the door. This canceling may be achieved, for example by the cable end emerging from the cable sheath, preferably under the action of a restoring spring, but the force thereof should be smaller than the force, acting in an opposite direction, of the spring in the region of the locking element.
A particularly expedient embodiment makes provision for the Bowden cable to be coupled via a pivotable deflecting lever to whose one end the cable of the Bowden cable is secured and whose other end can be carried along by drivers on the connecting elements which are designed as cables. A solution of this type permits the Bowden cable to be coupled to any desired point between the door handles and the door lock, as a result of which the length of the Bowden cable can be shortened and an addition of tolerances is avoided.